Mechanical switching device such as a circuit breaker and a safety device for the circuit breaker

Abstract

A safety device for mechanical switching devices such as circuit breakers which can be mounted on mounting surfaces or plugged into plug-in pin bases. The safety device ensures that the mechanical switching device is tripped both when it is being installed, and also when it is being removed.

What is claimed is: 
     
       1. A mechanical switching device for being removably mounted on a mounting structure, said switching device comprising: a housing;   a contact system disposed within said housing;   said contact system comprising a movable contact portion and a stationary contact portion;   both of said movable contact portion and said stationary contact portion being disposed within said housing;   both of said movable contact portion and said stationary contact portion being removable from a mounting structure along with said housing upon said switching device being removed from a mounting structure and installable on a mounting structure along with said housing upon said switching device being installed on a mounting structure;   apparatus to engage said movable contact portion with said stationary contact portion to provide a closed position of said switching device and to disengage said movable contact portion from said stationary contact portion to provide an open position of said switching device;   apparatus to move said contact system into a tripped position wherein said movable contact portion is disengaged from said stationary contact portion upon said switching device being installed on a mounting structure and upon said switching device being removed from a mounting structure;   said apparatus to move comprising: a latching mechanism operatively connected to said movable contact portion and being disposed to move said switching device into said tripped position;   a safety plunger having a longitudinal axis, a first end, and a second end disposed a substantial longitudinal distance from said first end;   said first end of said safety plunger for being disposed adjacent a mounting structure;   said second end of said safety plunger being operatively connected to said latching mechanism; and   said second end of said safety plunger comprising at least one cam having at least one portion extending along the longitudinal axis of said safety plunger.     
     
     
       2. The switching device according to claim 1 wherein: said at least one portion of said cam comprises a cam surface;   said cam surface comprising a first side and a second side disposed a substantial longitudinal distance from one another;   said at least one cam comprises: a first bevel disposed adjacent said first side of said cam surface; and   a second bevel disposed adjacent said second side of said cam surface; and     said cam surface extending between said first bevel and said second bevel.   
     
     
       3. The switching device according to claim 2 wherein: said latching mechanism comprises a latch, said latch being mounted for rotation and having an axis of rotation;   said latch being rotatable in a first rotational direction and a second rotational direction about the axis of rotation, the first rotational direction being opposite the second rotational direction;   said safety plunger being movable in a first direction during installation of said switching device on a mounting structure and a second direction during removal of said switching device from a mounting structure, the first direction being opposite the second direction; and   said cam being in contact with said latch such that, upon movement of said safety plunger in said first and second directions, said cam moves along said latch and moves said latch in said first rotational direction to move said switching device into said tripped position during removal of said switching device from a mounting structure and during installation of said switching device on a mounting structure.   
     
     
       4. The switching device according to claim 3 wherein: said housing comprises a bottom portion for being disposed adjacent a mounting structure, said bottom portion comprising a connection surface disposed adjacent said first end of said safety plunger;   said apparatus to move comprising a device to bias said safety plunger, said device to bias being disposed to provide a biasing force on said first end of said safety plunger in a direction away from said connection surface; and   said first end of said safety plunger extending out of said housing during removal of said switching device from a mounting structure.   
     
     
       5. The switching device according to claim 4 wherein during installation of said switching device on a mounting structure said first end of said safety plunger is moved towards said connection surface by a mounting structure against the biasing force of said device to bias. 
     
     
       6. The switching device according to claim 5 wherein: said first end of said safety plunger comprises an enlarged head, said enlarged head extending beyond said connection surface at least during removal of said switching device from a mounting structure;   said switching device being removable from a mounting structure in a first removal direction and being installable on a mounting structure in a second installing direction, the first removal direction being opposite the second installing direction; and   said apparatus to move being configured such that the longitudinal axis of said safety plunger is substantially parallel with respect to all of: the first removal direction; the second installing direction; the first direction of movement of said safety plunger and the second direction of movement of said safety plunger.   
     
     
       7. The switching device according to claim 6 wherein: said cam comprises a first depression and a second depression, said first depression being disposed adjacent said first side of said cam surface, said first bevel forming a transition between said cam surface and said first depression;   said second depression being disposed adjacent said second side of said cam surface, said second bevel forming a transition between said cam surface and said second depression; and   said switching device being in said tripped position upon said latch being in contact with said cam surface, and said switching device being in an untripped position upon said latch being in contact with one of said first and second depressions.   
     
     
       8. The switching device according to claim 7 wherein: said safety plunger comprises an intermediate portion disposed between said first end and said second end of said safety plunger, said intermediate portion comprising a stop extending outwardly from said intermediate portion; and   said switching device further comprising an abutment disposed within said housing and adjacent said intermediate portion of said safety plunger, said abutment being disposed to engage with said stop to prevent said safety plunger from exiting said bottom portion of said switching device.   
     
     
       9. The switching device according to claim 8 wherein said device to bias comprises a spring, said spring being disposed immediately adjacent said enlarged head of said safety plunger and being disposed about said first end of said safety plunger; said connection surface comprising a recess disposed therein, said recess having a cross-section, taken along the longitudinal axis of said safety plunger, said cross-section generally having the shape of an inverted T;   said recess having a first part and a second part, said first part being disposed nearer to said connection surface than said second part; and   said first part being configured to receive said enlarged head upon said switching device being installed on a mounting structure and said second part being configured to receive said spring upon said switching device being installed on a mounting structure.   
     
     
       10. The switching device according to claim 8 wherein: said device to bias comprises a spring, said spring being disposed immediately adjacent said enlarged head of said safety plunger and being disposed about said first end of said safety plunger;   said cam comprising an additional cam surface disposed adjacent said first depression, said additional cam surface having a first side and a second side disposed a substantial longitudinal distance from one another;   said additional cam surface comprising a first bevel disposed at said first side of said additional cam surface and a second bevel disposed at said second side of said additional cam surface;   said switching device being configured for being mounted on one of: a mounting plate; a mounting rail; and a plug-in pin base;   said latching mechanism further comprising a switch lock and a rocker arm both being associated with said latch;   said latch comprises a latching lever non-rotationally attached to said latch, said latching lever being in contact with said cam;   said cam surface and said additional cam surface being disposed substantially parallel to the longitudinal axis of said safety plunger;   said first and second depressions having a surface disposed substantially parallel to the longitudinal axis of said safety plunger; and   said first and second bevels of said cam surface and said first and second bevels of said additional cam surface all being disposed at a substantial angle with respect to the longitudinal axis of said safety plunger.   
     
     
       11. The switching device according to claim 6 wherein said apparatus to move further comprises: a mounting plate fixedly attached to said connection surface, said mounting plate having an opening disposed therein, said first end of said safety plunger being disposed in said opening;   said device to bias comprising a leaf spring, said leaf spring having a longitudinal axis, a first end and a second end disposed a substantial longitudinal distance from one another;   said first end of said leaf spring being fixedly attached to said mounting plate;   said second end of said leaf spring comprising a slot extending substantially parallel to the longitudinal axis of said leaf spring, said slot being disposed adjacent said opening of said mounting plate;   said leaf spring having a first side and a second side, said first side of said leaf spring facing said mounting plate and said second side of said leaf spring facing away from said first side of said leaf spring;   said enlarged head of said safety plunger being disposed at said second side of said leaf spring;   said safety plunger comprising an additional enlarged head disposed at said first side of said leaf spring, and a portion disposed between and connecting said enlarged head and said additional enlarged head; and   said portion disposed between said enlarged head and said additional enlarged head being disposed in said slot.   
     
     
       12. The switching device according to claim 11 wherein: said cam comprises a depression disposed adjacent said first side of said cam surface, said first bevel forming a transition between said cam surface and said depression;   said slot has one open end and one closed end, said closed end being disposed nearer to said first end of said leaf spring than said open end;   said mounting plate has a top portion, a bottom portion, a first edge, a second edge and a third edge, said first edge being substantially perpendicular to said second and third edges;   said first, second and third edges being disposed with respect to one another to form the general shape of a U;   said second and third edges being substantially parallel to one another;   said top portion and said bottom portion facing away from one another, said top portion facing said connection surface;   said leaf spring being disposed substantially parallel to said first edge and being disposed adjacent said first edge;   said first end of said leaf spring being fixedly attached to said bottom portion of said mounting plate;   said first edge comprising a plate extending from said first edge in a direction substantially perpendicular to said top and bottom portions of said mounting plate;   said plate being configured and disposed to prevent damage to said leaf spring;   said first end of said leaf spring being disposed adjacent said second edge of said mounting plate;   said apparatus to move further comprising a stopper disposed along said third edge of said mounting plate and being substantially parallel to said third edge of said mounting plate;   said stopper being disposed on said bottom portion of said mounting plate;   said stopper having a first terminal end and a second terminal end, said first terminal end being disposed adjacent said first end of said safety plunger;   said first terminal end of said stopper comprising a first leg and said second terminal end of said stopper comprising a second leg, each of said first and second legs having portions extending in a direction substantially perpendicular to said mounting plate;   said stopper comprising apparatus to permit sliding movement of said stopper along said bottom portion of said mounting plate;   said apparatus to permit comprising: a longitudinal slot disposed adjacent said second terminal end of said stopper; and   at least one pin disposed in said longitudinal slot and being fixedly fastened on said bottom portion of said mounting plate;     said first leg having a portion engageable with said second end of said leaf spring upon said stopper being moved in a direction away from said first edge of said mounting plate, said second leg thereby being in a position to block an attempt to mount said switching device on a mounting structure;   said first leg being alignable with said slot of said leaf spring upon movement of said stopper in a direction towards said first edge of said mounting plate;   said switching device being configured for being mounted on one of: a mounting plate; a mounting rail; and a plug-in pin base;   said latching mechanism further comprising a switch lock and a rocker arm both being associated with said latch;   said latch comprises a latching lever non-rotationally attached to said latch, said latching lever being in contact with said cam;   said cam surface being disposed substantially parallel to the longitudinal axis of said safety plunger;   said depression comprising a surface disposed substantially parallel to the longitudinal axis of said safety plunger; and   said first and second bevels of said cam surface being disposed at a substantial angle with respect to the longitudinal axis of said safety plunger.   
     
     
       13. Mechanical switching device for being removably mounted on a mounting surface, such as a plug-in pin base, mounting plate or mounting rail, the mechanical switching device having: a housing, movable contacts, stationary contacts, the movable contacts and the stationary contacts both being disposed within the housing, the movable contacts and the stationary contacts both being removable from a mounting surface along with the housing upon the mechanical switching device being removed from a mounting structure, a connection surface, an actuator mechanism with a rocker arm, switch lock and latching mechanism for the movable contacts of the mechanical switching device, a safety plunger located in the mechanical switching device, the safety plunger being movable in opposition to a spring force, the safety plunger being linked by means of one terminal area with the latching mechanism of the switch lock, the safety plunger being extendable with its other terminal area out of the mechanical switching device, the safety plunger causing a tripping of the mechanical switching device when the mechanical switching device is removed from the mounting surface, the terminal area of the safety plunger linked with the latching mechanism having an operating cam with at least one oblong and bilaterally bevelled control cam which is bevelled on both sides. 
     
     
       14. Mechanical switching device according to claim 13, wherein the latching mechanism has a latch which is mounted so that it can rotate or move to establish the tripped position of the mechanical switching device, which latch is linked to the operating cam of the safety plunger, and whereby during the installation or removal of the mechanical switching device, as a result of the movement of the safety plunger, the operating cam of the safety plunger can move along the latch and a rotational movement or displacement of the latch can be produced which guarantees that the mechanical switching device is in the tripped position during the installation or removal process. 
     
     
       15. Mechanical switching device according to claim 14, wherein the tripped state can be produced when the linkage is established between the latching mechanism and at least one control cam of the safety plunger, and the untripped state of the mechanical switching device can be produced when the linkage is established between the latching mechanism and a latching depression formed by the remaining part of the operating cam and between the control cams. 
     
     
       16. Mechanical switching device according to claim 15, wherein upon the mechanical switching device being removed from a mounting surface, the extendable terminal area of the safety plunger is moved in response to the action of a spring into a position where it extends beyond the connection surface of the mechanical switching device. 
     
     
       17. Mechanical switching device according to claim 16, wherein upon the mechanical switching device being installed onto a mounting surface, the extendable terminal area of the safety plunger is in a position in which it is supported against the mounting surface and is retracted into the mechanical switching device against the spring force of the spring. 
     
     
       18. Mechanical switching device according to claim 17, wherein: on the connection side of the mechanical switching device there is a recess which has at least one step for the location of the terminal area of the safety plunger and the compression spring when the mechanical switching device is in the installed position;   the longitudinal axis of the safety plunger is axially parallel to the direction of insertion and extraction respectively of the mechanical switching device, and to the direction of movement of the safety plunger; and   the safety plunger is enlarged to form a head on its terminal area which can be extended beyond the connection surface of the mechanical switching device.   
     
     
       19. Mechanical switching device according to claim 18, wherein the safety plunger, in the area of its longitudinal extension, has a projecting stop which interacts with a corresponding abutment in the mechanical switching device to prevent the safety plunger from falling out of the mechanical switching device. 
     
     
       20. Mechanical switching device according to claim 13, wherein the terminal end of the safety plunger which is linked with the latching mechanism has an operating cam with a plurality of control cams, which are located one after another in the longitudinal direction of the safety plunger.